36 Advanced SQL Challenges for Tech Interviews

Struggling with SQL interview coding rounds?

This Top 36 Advanced SQL Coding Questions Guide contains real interview problems asked in product companies, startups, and MNCs.

The guide helps you master complex SQL concepts used in real data roles.

Inside the guide you will learn:

✔ Advanced SQL interview questions

✔ Window functions explained

✔ Complex joins and subqueries

✔ Real business case SQL problems

✔ Query optimization techniques

✔ Step-by-step SQL solutions

This guide is perfect for:

• Data Analysts

• Data Scientists

• Business Analysts

• Data Engineers

• Students preparing for tech interviews

📊 Example Questions Inside the Guide

1️⃣ Find the Second Highest Salary

SELECT MAX(salary)

FROM employees

WHERE salary < (SELECT MAX(salary) FROM employees);

2️⃣ Find Duplicate Records

SELECT email, COUNT(*)

FROM users

GROUP BY email

HAVING COUNT(*) > 1;

3️⃣ Running Total Using Window Function

SELECT

order_date,

SUM(sales) OVER (ORDER BY order_date) AS running_total

FROM orders;

4️⃣ Top 3 Salaries per Department

SELECT *

FROM (

SELECT name, department, salary,

DENSE_RANK() OVER (PARTITION BY department ORDER BY salary DESC) rnk

FROM employees

) t

WHERE rnk <= 3;

5️⃣ Find Customers With No Orders

SELECT c.customer_id

FROM customers c

LEFT JOIN orders o

ON c.customer_id = o.customer_id

WHERE o.customer_id IS NULL;

📦 What Buyers Get

Your digital product should include:

• 36 Advanced SQL Interview Problems

• Detailed SQL solutions

• Window function examples

• Real business case queries

• Query optimization tips

• Practice dataset links